identity

the state of having unique identifying characteristics held by no other person or thing

2.

the individual characteristics by which a person or thing is recognized

3.

Also called numerical identity. the property of being one and the same individual: his loss of memory did not affect his identity

4.

Also called qualitative identity. the state of being the same in nature, quality, etc: they were linked by the identity of their tastes

5.

the state of being the same as a person or thing described or claimed: the identity of the stolen goods has not yet been established

6.

identification of oneself as: moving to London destroyed his Welsh identity

7.

(logic)

that relation that holds only between any entity and itself

an assertion that that relation holds, as Cicero is Tully

8.

(maths)

an equation that is valid for all values of its variables, as in (x – y)(x + y) = x² – y². Often denoted by the symbol ≡

Also called identity element. a member of a set that when operating on another member, x, produces that member x: the identity for multiplication of numbers is 1 since x.1 = 1.x = xSee also inverse (sense 2b)

9.

(Austral & NZ, informal) a well-known person, esp in a specified locality; figure (esp in the phrase an old identity)

c.1600, "sameness, oneness," from Middle French identité (14c.), from Late Latin (5c.) identitatem (nominative identitas) "sameness," from ident-, comb. form of Latin idem (neuter) "the same" (see identical); abstracted from identidem "over and over," from phrase idem et idem. [For discussion of Latin formation, see entry in OED.] Earlier form of the word in English was idemptitie (1560s), from Medieval Latin idemptitas. Term identity crisis first recorded 1954. Identity theft attested from 1995.